We have recently isolated 19-nor-desoxycorticosterone from the urine of rats with adrenal regeneration hypertension. Recent studies have shown that 19-nor-DOC is formed outside the adrenal gland and that the most likely precursor is 19-oxo-desoxycorticosterone (19-oxo-DOC) which is secreted by the rat adrenal. This steroid has been shown to have 50% the mineralocorticoid potency of DOC. Our research plans include the validation of an assay for 19-oxo-DOC and its use for their measurements during the development of adrenal regeneration hypertension. In addition, we will study the interaction of this steroid with the classical corticoid receptors in the kidney as well as the possibility of a specific receptor for 19-oxo-DOC in the kidney. An additional study will be done in which we will test the hypertensinogenic activity of 19-oxo-DOC by chronic injection into rats and determining their blood pressure response. These studies will determine the role of these newly isolated steroids in the development of adrenal regeneration hypertension.